System of distribution.



No. 850,217. PATENTED APR. 16, 1907.

B. FRANKENFIELD.

SYSTEM OF DISTRIBUTION.

APPLICATION rum) 11.17, 1906.

2 SHEETSSHEET 1.

JAM/ENTER .Budd f'Fankery z'eld.

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ATTURNEY PATENTEDAPR. 16, 1907. B. FRANKENFIELDL SYSTEM OF DISTRIBUTION.

APPLICATION FILED EAR. 17. 1908.

2 SHEETS-SHEET 2.

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BUDD FRANKENFIELD, OF NORWOOD, OHIO, ASSIGNOR TO ALLIS-CHAL- MERSCOMPANY, A'CORPORATION OF NEW JERSEY, AND THE BULLOCK ELECTRICMAVUFACTURIN G COMPANY, A CORPORATION OF OHIO.

.SYSTEM OF DISTRIBUTION- Specification of Letters Patent.

Application filed March 17, 1906. Serial No. 306,573.

Patented April 16, 1907.

T 0 all li'hmn 1'1 fluty concern;

' Be it known that I, BUDD FRANKENFIELD, a citizen of the United States,residing at Norwood, in the county of Hamilton and State of Ohio, haveinventedcertain new and useful Improvements in Systems of Distribution,of which the following is a full, clear,

and exact specification.

My invention relates to systems of distribution in whichdynamoelectric-machine units are employed for transforming purposes, andespecially. to the novel means whereby such units can be compounded tosupply the proper voltage to the translating devices under anyconditions of load.

Dynamo-electric-machine units with motor and generator windings, such asdynamotors and motor-generators having shunt characteristics, arefrequently used in transforming power. The dynamotor, as is .well known,has but one magnetic field and two armatures or two armature-windings onthe same core. The motor-generator, on the other hand, has two separatearmatures located in independent magnetic fields. Al'- though thedynamotor has several distinct advantages over the motor-generator itsfield of application is somewhat limited, for the reason that shuntcharacteristics only are obtainable. Compounding efiects cannot beobtained from a dynamotor by adding series windings in the customarymanner, for the reason that the'eflect of the series field upon Q themotor-armature winding would neutralize the effect upon thegenerator-armature winding. In other words, theeflect of theserieswindings would be to change the speed of the unit without changingthe generated voltage.

Since in a motor-generator unit the motor and generator fields areseparate, the field of the generator can be provided with serieswindings, and compound characteristics can be obtained as long as theseries-wound machine acts as a generator and the other Inachine acts asa motor. It follows that such a unit could not be employed in case themotor and generator relation of the two machines was intended to bereversed, for the reason that on reversal the series-wound generatorwould become a differential motorand the unit would be in dangerof-running away or of racing, especially on overload. There-.shunt-wound, and accordingly fore motor-generators employed asbalancers in multiple voltage systems are usually close voltageregulation is impossible. I

The object of my invention is to provide means whereby thedynamo-electric-machine units having motor and generator windings,motor-generators such as dynamotors and employed for transformingcompounded and in such a matter for what ployed there will overload.

My invention consists in certain novel purposes, can be manner that nopurposes the units are embe no danger of racing on combinations andarrangements of parts described in the specili'cation, and set forth inthe appended claims.

For a better understanding of my invention reference is had to theaccompanying drawings, in which Figure 1 is a diagram of a two-wiresinglevoltage system of distribution in which a dynamotor compounded inaccordance with my invention is employed. gram of a three-wiremultiple-voltage system of distribution provided with adynamotor-balancer compounded according to -my invention. Fig. 3 is adiagram of a threewire multiple voltage system, showing adynamotor-balaneer compounded in a slightly-different manner; and Fig. 4is a diagram of a three-wire multiple-voltage sys' tem in. which amotor-generator balanc'er compounded according to my invention isemployed.

At 10 in Fig. 1 is shown a main source of currentin this case ageneratorand at 1 1 a dynamo-electrie-machine unit adapted to receive currentfrom said generator at a certain voltage and to supply current to thefeederconductors 12 and 13 at a different voltage. The unit 'in thiscase consists of a shunt-- wound dynamotor 14 and a small auxiliaryseries generator 15, the purpose of which will be explained later, Thedynamotor has a single armature-core 16, adapted to carry the motor andgenerator armature windings. (Not shown.) At 17 is shown the .motor-'commutator and at '18 the motor-brushes, by which current is suppliedtothe motor-armature winding from the main'source of current 10. At 19 atthe opposite end of the dyna-' motor is shown a second commutatoradapted Fig. .2 is a diatages are in series and addative,

to be connected to the generator armature Heretofore dynamotors suppliedfrom a source of constant voltage could not be used for transformingpurposes in case it was necessary to supply to the translating devicesvariable current at constant voltage. Since in a dynamotor sparking isalmost negligible, for the reason that the motor-an mature reaction isalmost entirely neutralized by the generator-armature reaction, andsince such amachine is lighter and cheaper and the friction, fieldresistance, and core losses are less than in other apparatus used forthis purpose, as :a motor-generator, it is highly desirable to providemeans whereby the dynamotor can be compounded in order that its field ofa plicationmay "be enlarged. I accomplish this result by employing incon- I nection with the dynamotor a small auxiliary generator 15, havinseriescharacteristics and so connected to t e generator-winding of thedynamotor that the two generatoivot s is shown, the generator is mountedto rotate with the dynamotor. The generator 15 is provided with anarmature 22, commutator 23, brushes 24, and series field-Winding 25. Thearmature-winding and field-winding are connected in series with thegenerator-'arma-= The series ture winding of the dynamotor. held can beadjusted to provide for any degree of compounding or overcompounding.

' The purpose of this generator is simply to supply the extra voltagenecessary to compensate for an increased voltage drop in thegenerator-armature winding and feeder-conductors when the loadincreases. Very little work is required of the generator 15, andtherefore it can be small and inexpensive and can be easily designed sothat there is little or no sparking.

In Fig. 2 the dynamotor, compounded as in the preceding case, isemployed as a balancer in a multiple-voltage system. Thefeeder-conductors of the multiple-voltage system are shown at 26, 27,and 28. The system may have either symmetrical or unsymmetricalvoltages. The compounded unit consists, as in the receding ease, of adynamotor 29 and a smal series auxiliary generator 30. The armaturewindings of the dynamotor are connected in series across the mainconductors 26 and 28 by conductors 3 1, 32, and 33. The dynamotor isprovided with a shunt field-winding 34, also connected across theconductors 26 and 28.

6 5 One of the brushes of the auxiliarygenerator is connected bytconductor 36 to the conductor 32, joining the armature-windings of thedynamotor. The other brush 37 is connected to the series field-winging38 and to conductor 27. Itis seen that if the'loads are balanced thereis no current passing through conductor 27 and series field-winding 38,and therefore no voltage is supplied by the auxiliary generator 30. Incase, however, the loads are unbalanced the auxiliary generator 30supples voltage to one side of the system or the other,'dependingupon'the direction of the current-flow through the conductor 27' andseries field-winding 38. By means of the voltage supplied by theauxiliary generator the voltage bet-ween any two conductors can bemaintained substantially at the proper pre determined value, even if theloads are greatly unbalanced. It is evident that this same principle canbe applied to a multiplevoltage system of distribution having more thanthree conductors.

Reference is now had to Fig. 3, which shows a multiple-voltage systemand a balancer consisting of a dynamotor compounded in a manner slightlydifferent from that shown in Fig. 2. The conductors of themultiple-voltage system are shown at 39, 40, and 41. Thebalancerconsists of a dynamotor 42 and an auxiliarygenerator 43. Thearmature-windings of the dynamo or are connected by conductors 44, 45,and 46 between the conductors 39 and 41 of the multiplevoltage system,as in the preceding case. Included in the conductor are twooppositely-woundseries field-windings 47 and 48 for the auxiliarygenerator 43 of the dynamo-electric-machine unit. The brushes 49 and 50of the auxiliary generator are connected, respectively, to conductor .45at a point between these two oppositely-wound series field-windings andto the neutral or compensating conductor 40. It is seen that when theloads are balanced and no current is flowing in the conductor 40 thatthe currents passing through the two series field windings 47 and 48 areequal. Therefore the eifect of one winding exactly neutralizes theeffect of the other winding and the generator 43 supplies no voltage tothe conductors of the system. In case, however, the loads becomeunbalanced more current passes through one of the field-windings thanthe other for the reason that more current passes to the motor-armaturewinding than to the generator-armature winding, since the motor mustsupply the losses of both ma chines. .The excess of current in the onewinding over the current in the other depends upon the losses intlie twomachines.-

and varies with the load in sucha manner that the voltage supplied bythe auxiliary generator varies substantially with the degree ofunbalancing. There are only slight differences of potential betweenfield-wind- ICC -ner.

ferences in voltage between the various con' ductors may be maintainedpractically constant. For the same reason that a ditl'erential motor isliable to run away on overload 'a balancer compounded in the ordinarymanner is liable to run away or race when the loads are unbalanced. Amotor-generator 'balancer compounded according to myinvention has notendency to race or run away.

In Fig. 4 is shown a balancer unit consisting 1 of a motor-generator setand an auxiliary generator for compounding purposes. The conductors ofthe multiple-voltage'system are shown at 51, 52, and 53. The two maindynamo electric machines of the motor-generator are shown at 54 and 55and the auxiliary generator is shown at 56.

The armacure-windings of machines 54 and 55 are connected across theconductors 51 and 53 by conductors 57, 58, and 59 in the usual'man- Themachines are provided with shunt field-windings 60 and 61. Brush 62 ofthe auxiliary generator is in this case connected to serieswinding 63and to'conductor 58, and brush 64 is connected directly to the neutralor compensating conductor 52. The operation of the compoundedmotor-generator is precisely the same as that of the compoundeddynamo-tor in Fig. 2.. When the loads are balanced, no current passesthrough the series winding-63 of the auxiliary generator, and hence thelatter supplies no voltage to either side of the system. In case,however, the loads become unbalanced current flows through thecompensating conductor 52 and through the main machines of the balancer,one of said machines acting as a motor and the other acting as agenerator to supply the balancing voltage. Voltage is now also suppliedby the auxiliary generator to one side or the other of the system,depending upon which side is the more heavily loaded, and the auxiliarygenerator is so connected that the direction of current in thecompensating conductor magnetizes the field' of the auxiliary generatorin a direction such that the voltage developed is in series and is addedto that of the main machine of the balancer, which is acting as agenerator. Thus the voltages are maintained practically at theirpredetermined values. It is seen that the motor-generator compounded inthis manner cannot race or run away no matter What the degree ofunbalancing is, for the reason that the series magnetic circuit isseparate from both the other circuits, and hence the main e Idynamo-electric machine of the balancer, which is acting as a motor, cannever have difi'erential fields.

I do not desire to be confined to the exact details shown, as manychanges could be made without departing from the spirit and scope of myinvention.

What I claim as new, and desire to secure by Letters Patent, is

1. In combination, a dynamo-electric-machine unit having motor andgenerator armature windings, a fieldwinding, an auxiliary generatorarmature winding, and a separate field-winding therefor, said twofield-windings producing shunt and series magnetic efiects'.

2-. In combination, a dynamo electric-machine unit comprising motor andgenerator armature windings having shunt field excitation, and anauxiliary generator-winding in series with the first-mentionedgeneratorwinding and having series field excitation whereby the unit hasa compound characteristic.

3. In combination, a dynamo-clectric-machine unit having main motor andgenerator armature windings having shunt field excitation, and anauxiliary generator comprising an armature and a separate magneticfiel'd, the winding of said auxiliary generatorarmature being connectedto the 'lTlaiIl genorator-armature winding and having'a field excitationdepending on load conditions.

4. In a system of distribution, a main source of current,feeder-conductors, a dynamo-electric-machine unit connected to saidsource of current, and adapted to supply current to saidfeeder-conductors, said unit having main motor and generator armaturewindings having substantially constant field excitation, and anauxiliary generator comprising an armature winding and one or morefield-windings for producing a field excitation which variessubstantially with the load conditions.

5.; In a system of distribution, a main source of current andsupply-circuit, feederconductors, a dynamo-electric-machine unit havingthree separate armature-windings, one of said windings being connectedto the source of current and the other two being connected to thefeeder-conductors and adapted to supply current thereto, and means forcreating independent fields for said two lastnamed windings, one of saidfields varying with the pressure of the main supply-circuit and theother varying with the current flow ing in a feeder-conductor.

6. In a system of distribution, a main source of current-supply,feeder-conductors, a dynamo-electric-machine unit comprising two mainarmature-windings, one or more shunt field windings therefor, and anauxiliary compounding-generator having an armature-Winding and one ormore field-Wind- III ings for creating 'a magnetic fieldwhich varieswith load conditions.

7. In a system of distribution, a main source of current-supply,feeder-conductors, a dynaino-electric-anachine unit comprising two mainarmature-windings and one or more shunt field-windings, one of saidarmature-windings being adapted to receive current from said source ofsupply and the other being adapted to supply current to the feederconductors, and an auxiliary armature-Winding located in a magneticfield which varies substantially with the current in a feederconductor.

8. In a system of distribution, a main source of current-supply,feeder-conductors, a dynamoelectric3nachine unit comprising twoarmature-windings and one or more shunt field-windings, and a separategenerator having a series field-Winding and an ar mature-winding inseries with one of the other windings.

9. In a systern of distribution,. a main source of current,feeder-conductors, and a dynamo-electric-niachine unit adapted toreceive current from saidlnain source and to supply current' to the.feeder-conductors, said unit comprising a motor-armature winding and agenerator-armature winding having shunt field excitation, and anauxiliary generator-armature winding having series excitation, the twogenerator armature windings being in series.

10. In a system of distribution, a main source of current, a pluralityof feeder-conductors, a dynamo-electric1nachine unit adapted to receivecurrent from said main source and to supply current to the feederconductors, said unit comprising two main armature-windings and one ormore shunt field-windings, and an auxiliary generator having anarmature-winding and a fieldwinding adapted to be connected in serieswith one of the main armature-windings and with one of thefeeder-conductors.

'4 In testimony whereof I affix my signature in the presence of twowitnesses.

BUDD FRANKEN FIELD.

WVitnesses ARTHUR F. Kwis, FRED J. KINsEY.

